oil pressure gauge acting up

hey guys.. in my 2006 gmc seirra my oil pressure gauge just pegged to 80 one day last week. the truck runs fine,no check engine lights or any other warnings... just today it started sweeping from 0 to 80 randomly. like i said before, no warnings, lights or performance issues.. i know its just an electrical issue, but my question is where?? the stepper motor? the pressure switch?? wiring between the two?? ANY input is appreciated!!
thanks!!

thanks for all your help so farguys!! so upon driving home from work tonight, the oil pressure needle was goin all over the place.. the scary (at least for me) thing is the "low oil pressure" message came across the info center.. is there any chance that the gauge going to zero is causing that mesage to come across, or are they seperate systems??
ps.. oil level was 1/2 in the hash marks, which should be fine, but i added 1/2 qt just to be safe, no knocking,overheating due to lack of lubrication.. nothing phiscally wrong just wacky indications...